This invention relates to the treating of fresh meats to enhance handling and storage thereof from the slaughtering of the animal to the marketing of the retail meat product.
Centralized fabrication of carcasses into primal and subprimal cuts, packaging of these cuts and their distribution to the wholesale and retail outlets is rapidly becoming more popular in the meat packing industry. Centralization of fresh meat marketing and distribution has provided solutions to problem areas such as the shortage of skilled workers, the rising costs of equipment and transportation, decline in reliability of transportation, and intensified governmental regulations. However, microbial contamination resulting in the reduction of product shelf-life continues to be a significant problem. Further reduction in shrink and trim losses is also desirable.
Fresh meat provides an excellent medium for microbial growth. Initial contamination of the fresh meat is received because of the great amount of human contact and equipment exposure during slaughter, chilling, processing, transportation and retail displays. The time lapse between contamination from human and equipment exposure at the time of prefabrication at a centralized processing unit and the time of sale at the retail level allows for microbial multiplication and potential spoilage.
Thus, there is a long felt need in the meat packaging industry for reducing bacterial numbers and/or controlling their multiplication to avoid spoilage and to increase the subsequent retail shelf-life of meats. Microbial decontamination of fresh meats is also necessary to meet the impending microbial standards for meat products. These standards are set by the United States Government and are imminent as soon as acceptable levels of contamination are determined and rapid and reproduceable monitoring techniques can be established. Decontamination procedures are especially for the reduction of potentially hazardous organisms such as salmonella, which may have very low tolerances.
Another problem associated with the processing of meat is dehydration. The evaporation of moisture, or shrink, from carcasses during the initial chilling period after slaughter results in a one-and-one-half to three percent loss in carcass weight. Shrink continues to accumulate through the transportation and marketing channels. Such shrink costs the meat industry millions of dollars each year. Most of the loss is passed on to consumers in the form of higher prices.
The problems of shrink and microbial contamination are interrelated because attempts to control one problem often allows the other one to flourish. For example, increased air circulation and colder air during chilling retards microbial growth. However, this procedure increases shrink. Consequently, the industry has been seeking procedures for the reduction of both shrink and microbial growth with respect to the processing of meat products.
Under commercial conditions with good sanitation, it is not economically feasible to remove all sources of contamination or maintain perfect environmental conditions to retard microbial growth. To reduce the contamination to acceptable levels, various packaging procedures and decontamination techniques have been investigated.
The prior art has recommended the use of impermeable packages for prolonging the acceptability of meat products. For example, a vacuum has been used in combination with gas impermeable packaging. Soft film wraps such as polyvinyl chloride have been used to wrap sheep, hogs and beef to reduce shrinkage loss during shipment. However, the increased moisture on the surface of the meat wrapped with these films resulted in increased microbiological growth. An intermittent spray of a chlorine wash has been used in combination with the film wraps in an effort to reduce shrink and microbial contamination.
Chemical decontamination treatments including the application of chlorine, stannous chloride, hydrogen peroxide, and other weak acids have been used on lamb, pork, and beef carcasses. Ultraviolet light treatment has also been used to reduce the load of microorganisms but has increased fat oxidation. The other chemical treatments have been of limited value.
Numerous other techniques have also been tried but none have been able to effectuate the desired results of reducing shrink and at the same time eliminating microbial contamination. See U.S. Pat. Nos. 2,763,557, 2,819,975, 3,814,821 and 2,948,623 as typical prior art methods for treating meat products.
The processing of freshly slaughtered meat from body temperature to a desired cooled storage temperature poses several problems. The freshly slaughtered animal carcass is washed, hung, and must be cooled down from its body temperature which is about 104.degree. F to a temperature just above freezing. The cooled storage temperature may be below 40.degree. F. It is desired to eliminate the problem of the souring of the meat around the bone and the formation of crust on the surface of the meat. During the heat transfer process while the meat is being chilled, there is the problem of dehydration.
Throughout the meat processing industry, a cloth shroud soaked in brine is hand-wrapped around the carcass. Stainless steel pins are used to hold the salt water soaked cloth in place. The application of this cloth or shroud includes large expenditures with respect to labor and equipment and contamination problems due to handling. U.S. Pat. No. 2,697,664, 3,070,448, and 3,124,468 show various wrapping procedures which the present invention eliminates.